Regiocontrolled Gold-Catalyzed [2+2+2] Cycloadditions of Ynamides with Two Discrete Nitriles to Construct 4-Aminopyrimidine Cores
作者:Somnath Narayan Karad、Rai-Shung Liu
DOI:10.1002/anie.201405312
日期:2014.8.18
Reported herein is the novel gold‐catalyzedintermolecular [2+2+2] cycloaddition of ynamides with two discrete nitriles to form monomeric 4‐aminopyrimidines, which are pharmaceutically important structural motifs. The utility of this new cycloaddition is demonstrated by the excellent regioselectivity obtained using a variety of ynamides and nitriles.
Cp*Co(<scp>iii</scp>)-Catalyzed oxidative [5+2] annulation: regioselective synthesis of 2-aminobenzoxepines <i>via</i> C–H/O–H functionalization of 2-vinylphenols with ynamides
作者:Xiang-Lei Han、Xu-Ge Liu、E Lin、Yunyun Chen、Zhuangzhong Chen、Honggen Wang、Qingjiang Li
DOI:10.1039/c8cc06807k
日期:——
A Cp*Co(III)-catalyzed [5+2] C–H annulation reaction of 2-vinylphenols with ynamides was developed. The reaction led to the efficient synthesis of valuable 2-aminobenzoxepines in high regioselectivity. Mild reaction conditions, good functional group tolerance, and moderate to good yields were observed. The synthetic utility was demonstrated by a gram-scale synthesis and further transformations of the
Zn(II)-Catalyzed One-Pot Synthesis of Coumarins from Ynamides and Salicylaldehydes
作者:Huen Ji Yoo、So Won Youn
DOI:10.1021/acs.orglett.9b01181
日期:2019.5.3
A highly efficient and straightforward synthesis of diversely substituted coumarins from ynamides and salicylaldehydes in the presence of Zn(II) catalyst has been developed. The sulfonamide moiety of ynamides was successfully recycled in this process, serving as an effective traceless directing group for high regioselectivity in the bond-forming event. The advantages of this protocol are good functional
Harnessing the Polarizability of Conjugated Alkynes toward [2 + 2] Cycloaddition, Alkenylation, and Ring Expansion of Indoles
作者:Tapas R. Pradhan、Hong Won Kim、Jin Kyoon Park
DOI:10.1021/acs.orglett.8b02230
日期:2018.9.7
Reported is the utilization of electronically biased conjugated alkynes in the development of highly diastereo- and regioselective dearomative [2 + 2] cycloadditions, alkenylations, and ring expansions of electron-rich indoles. Regioselective protonations of cross- and linear-conjugated alkynes were found to be crucial for accessing various cyclobutene-fused indoline and alkenylated indole derivatives
据报道,在高度非对映和区域选择性脱芳香性[2 + 2]环加成,烯基化和富电子吲哚的环扩展中,利用电子偏置的共轭炔烃。发现交叉和线性共轭炔的区域选择性质子化对于获得各种环丁烯稠合的二氢吲哚和烯基化的吲哚衍生物至关重要。此外,由炔酮成功合成的[2 + 2]酮加合物的容易的环扩展提供了1 H-苯并[ b ]氮杂骨架。
Gold-Catalyzed [4+2]- and [3+3]-Annulations of Ynamides with 1-Yn-3-ols to Access Six-Membered Carbocycles and Oxacycles <i>via</i>
Three Distinct Cyclizations
作者:Sovan Sundar Giri、Rai-Shung Liu
DOI:10.1002/adsc.201700784
日期:2017.10.4
and 1‐yn‐3‐ols are described; the resulting carbo‐ and heterocycles were produced efficiently in one‐pot operations using a gold catalyst. The chemoselectivities of these annulations are controlled by variations of the substituents of the ynamides and the 1‐yn‐3‐ols. This reaction sequence involves initial alkoxylations of ynamides, followed by Claisen rearrangement of propargylic enolethers, and ends